1. Programmer's Guide
  2. OCI Cartridge Functions
  3. Cartridge Services — File I/O Interface

Cartridge Services — File I/O Interface

Lists and describes cartridge services file I/O interface functions.

Table 29-5 lists the file I/O interface functions that are described in this section.

Table 29-5 File I/O Interface Functions

Function Purpose

OCIFileClose()

Close a previously opened file

OCIFileExists()

Test to see if the file exists

OCIFileFlush()

Write buffered data to a file

OCIFileGetLength()

Get the length of a file

OCIFileInit()

Initialize the OCIFile package

OCIFileOpen()

Open a file

OCIFileRead()

Read from a file into a buffer

OCIFileSeek()

Change the current position in a file

OCIFileTerm()

Terminate the OCIFile package

OCIFileWrite()

Write buflen bytes into the file

See Also:

Oracle Database Data Cartridge Developer's Guide for more information about using these functions

OCIFileObject

The OCIFileObject data structure holds information about the way in which a file should be opened and the way in which it is accessed after it has been opened. When this structure is initialized by OCIFileOpen(), it becomes an identifier through which operations can be performed on that file. It is a necessary parameter to every function that operates on open files. This data structure is opaque to OCIFile clients. It is initialized by OCIFileOpen() and terminated by OCIFileClose().

OCIFileClose()

Closes a previously opened file.

Purpose

Closes a previously opened file.

Syntax

sword OCIFileClose( void          *hndl, 
                    OCIError      *err, 
                    OCIFileObject *filep );

Parameters

hndl (IN)

The OCI environment or user session handle.

err (IN/OUT)

The OCI error handle. If there is an error, it is recorded in err, and this function returns OCI_ERROR. Diagnostic information can be obtained by calling OCIErrorGet().

filep (IN/OUT)

A pointer to a file identifier to be closed.

Comments

Once this function returns OCI_SUCCESS, the OCIFileObject structure pointed to by filep is destroyed. Therefore, you should not attempt to access this structure after this function returns OCI_SUCCESS.

Returns

OCI_SUCCESS; OCI_INVALID_HANDLE; or OCI_ERROR.

Related Topics

OCIFileExists()

Tests to see if the file exists.

Purpose

Tests to see if the file exists.

Syntax

sword OCIFileExists( void     *hndl, 
                     OCIError *err, 
                     OraText  *filename, 
                     OraText  *path, 
                     ub1      *flag );

Parameters

hndl (IN)

The OCI environment or user session handle.

err (IN/OUT)

The OCI error handle. If there is an error, it is recorded in err, and this function returns OCI_ERROR. Diagnostic information can be obtained by calling OCIErrorGet().

filename (IN)

The file name as a NULL-terminated string.

path (IN)

The path of the file as a NULL-terminated string.

flag (OUT)

Set to TRUE if the file exists or FALSE if it does not.

Returns

OCI_SUCCESS; OCI_INVALID_HANDLE; or OCI_ERROR.

Related Topics

OCIFileFlush()

Writes buffered data to a file.

Purpose

Writes buffered data to a file.

Syntax

sword OCIFileFlush( void          *hndl
                    OCIError      *err, 
                    OCIFileObject *filep );

Parameters

hndl (IN)

The OCI environment or user session handle.

err (IN/OUT)

The OCI error handle. If there is an error, it is recorded in err, and this function returns OCI_ERROR. Diagnostic information can be obtained by calling OCIErrorGet().

filep (IN/OUT)

A file identifier that uniquely references the file.

Returns

OCI_SUCCESS; OCI_INVALID_HANDLE; or OCI_ERROR.

Related Topics

OCIFileGetLength()

Gets the length of a file.

Purpose

Gets the length of a file.

Syntax

sword OCIFileGetLength( void     *hndl, 
                        OCIError *err, 
                        OraText  *filename, 
                        OraText  *path, 
                        ubig_ora *lenp );

Parameters

hndl (IN)

The OCI environment or user session handle.

err (IN/OUT)

The OCI error handle. If there is an error, it is recorded in err, and this function returns OCI_ERROR. Diagnostic information can be obtained by calling OCIErrorGet().

filename (IN)

The file name as a NULL-terminated string.

path (IN)

The path of the file as a NULL-terminated string.

lenp (OUT)

Set to the length of the file in bytes.

Returns

OCI_SUCCESS; OCI_INVALID_HANDLE; or OCI_ERROR.

Related Topics

OCIFileInit()

Initializes the OCIFile package.

Purpose

This function must be called before any other OCIFile routine is called.

Syntax

sword OCIFileInit( void     *hndl, 
                   OCIError *err );

Parameters

hndl (IN)

The OCI environment or user session handle.

err (IN/OUT)

The OCI error handle. If there is an error, it is recorded in err, and this function returns OCI_ERROR. Diagnostic information can be obtained by calling OCIErrorGet().

Returns

OCI_SUCCESS; OCI_INVALID_HANDLE; or OCI_ERROR.

Related Topics

OCIFileOpen()

Opens a file.

Purpose

Opens a file.

Syntax

sword OCIFileOpen( void            *hndl, 
                   OCIError        *err, 
                   OCIFileObject  **filep, 
                   OraText         *filename, 
                   OraText         *path, 
                   ub4              mode, 
                   ub4              create, 
                   ub4              type );

Parameters

hndl (IN)

The OCI environment or user session handle.

err (IN/OUT)

The OCI error handle. If there is an error, it is recorded in err, and this function returns OCI_ERROR. Diagnostic information can be obtained by calling OCIErrorGet().

filep (IN/OUT)

The file identifier.

filename (IN)

The file name as a NULL-terminated string.

path (IN)

The path of the file as a NULL-terminated string.

mode (IN)

The mode in which to open the file. Valid modes are

OCI_FILE_READ_ONLY

OCI_FILE_WRITE_ONLY

OCI_FILE_READ_WRITE

create (IN)

Indicates if the file is to be created if it does not exist. Valid values are:

OCI_FILE_TRUNCATE — Create a file regardless of whether it exists. If the file exists, overwrite the existing file.

OCI_FILE_EXCL — Fail if the file exists; otherwise, create a file.

OCI_FILE_CREATE — Open the file if it exists, and create it if it does not.

OCI_FILE_APPEND — Set the file pointer to the end of the file prior to writing. This flag can be used with the logical operator OR with OCI_FILE_CREATE.

type (IN)

File type. Valid values are:

OCI_FILE_TEXT

OCI_FILE_BIN

OCI_FILE_STDIN

OCI_FILE_STDOUT

OCI_FILE_STDERR

Returns

OCI_SUCCESS; OCI_INVALID_HANDLE; or OCI_ERROR.

Related Topics

OCIFileRead()

Reads from a file into a buffer.

Purpose

Reads from a file into a buffer.

Syntax

sword OCIFileRead( void          *hndl, 
                   OCIError      *err, 
                   OCIFileObject *filep, 
                   void          *bufp, 
                   ub4            bufl, 
                   ub4           *bytesread );

Parameters

hndl (IN)

The OCI environment or user session handle.

err (IN/OUT)

The OCI error handle. If there is an error, it is recorded in err, and this function returns OCI_ERROR. Diagnostic information can be obtained by calling OCIErrorGet().

filep (IN/OUT)

A file identifier that uniquely references the file.

bufp (IN)

The pointer to a buffer into which the data is read. The length of the allocated memory is assumed to be bufl.

bufl (IN)

The length of the buffer in bytes.

bytesread (OUT)

The number of bytes read.

Comments

As many bytes as possible are read into the user buffer. The read ends either when the user buffer is full, or when it reaches end-of-file.

Returns

OCI_SUCCESS; OCI_INVALID_HANDLE; or OCI_ERROR.

Related Topics

OCIFileSeek()

Changes the current position in a file.

Purpose

Changes the current position in a file.

Syntax

sword OCIFileSeek( void          *hndl, 
                   OCIError      *err, 
                   OCIFileObject *filep, 
                   uword          origin, 
                   ubig_ora       offset, 
                   sb1            dir );

Parameters

hndl (IN)

The OCI environment or user session handle.

err (IN/OUT)

The OCI error handle. If there is an error, it is recorded in err, and this function returns OCI_ERROR. Diagnostic information can be obtained by calling OCIErrorGet().

filep (IN/OUT)

A file identifier that uniquely references the file.

origin(IN)

The starting point from which to seek. Use one of the following values:

OCI_FILE_SEEK_BEGINNING (beginning)

OCI_FILE_SEEK_CURRENT (current position)

OCI_FILE_SEEK_END (end of file)

offset (IN)

The number of bytes from the origin where reading begins.

dir (IN)

The direction to go from the origin.

Note:

The direction can be either OCIFILE_FORWARD or OCIFILE_BACKWARD.

Comments

This function allows a seek past the end of the file. Reading from such a position causes an end-of-file condition to be reported. Writing to such a position does not work on all file systems. This is because some systems do not allow files to grow dynamically. They require that files be preallocated with a fixed size. Note that this function performs a seek to a byte location.

Returns

OCI_SUCCESS; OCI_INVALID_HANDLE; or OCI_ERROR.

Related Topics

OCIFileTerm()

Terminates the OCIFile package.

Purpose

This function must be called after the OCIFile package is no longer being used.

Syntax

sword OCIFileTerm( void     *hndl, 
                   OCIError *err );

Parameters

hndl (IN)

The OCI environment or user session handle.

err (IN/OUT)

The OCI error handle. If there is an error, it is recorded in err, and this function returns OCI_ERROR. Diagnostic information can be obtained by calling OCIErrorGet().

Returns

OCI_SUCCESS; OCI_INVALID_HANDLE; or OCI_ERROR.

Related Topics

OCIFileWrite()

Writes buflen bytes into the file.

Purpose

Writes buflen bytes into the file.

Syntax

sword OCIFileWrite( void          *hndl, 
                    OCIError      *err, 
                    OCIFileObject *filep, 
                    void          *bufp, 
                    ub4            buflen, 
                    ub4           *byteswritten );

Parameters

hndl (IN)

The OCI environment or user session handle.

err (IN/OUT)

The OCI error handle. If there is an error, it is recorded in err, and this function returns OCI_ERROR. Diagnostic information can be obtained by calling OCIErrorGet().

filep (IN/OUT)

A file identifier that uniquely references the file.

bufp(IN)

The pointer to a buffer from which the data is written. The length of the allocated memory is assumed to be buflen.

buflen (IN)

The length of the buffer in bytes.

byteswritten (OUT)

The number of bytes written.

Returns

OCI_SUCCESS; OCI_INVALID_HANDLE; or OCI_ERROR.

Related Topics